{"id":3711,"date":"2012-06-13T10:15:19","date_gmt":"2012-06-13T10:15:19","guid":{"rendered":"https:\/\/blogs.nature.com\/thescepticalchymist\/?p=3711"},"modified":"2012-06-13T10:15:19","modified_gmt":"2012-06-13T10:15:19","slug":"ambiguous-bromine","status":"publish","type":"post","link":"https:\/\/blogs.nature.com\/thescepticalchymist\/2012\/06\/ambiguous-bromine.html","title":{"rendered":"Ambiguous bromine"},"content":{"rendered":"<p align=\"left\">At first sight bromine seems to be \u2018just another halogen\u2019, a helpful counter-anion or leaving group in S<sub>N<\/sub>2 or cross-coupling reactions. Of course this isn\u2019t the whole story, as Matt Rattley \u2014 a chemistry student at the <a href=\"https:\/\/www.ox.ac.uk\/\">University of Oxford<\/a> and the author of the winning essay on bromine for last year\u2019s <a href=\"https:\/\/blogs.nature.com\/thescepticalchymist\/2011\/10\/essay_competition_and_the_winn_1.html\">contest<\/a> \u2014 points out in his <a href=\"https:\/\/www.nature.com\/nchem\/journal\/v4\/n6\/full\/nchem.1361.html\">article<\/a> (subscription required).<\/p>\n<p align=\"left\">Bromine was isolated independently by Carl Jacob L\u00f6wig from a mineral water spring, and Antoine Balard from seaweed, in 1825 and 1826. Having identified that he\u2019d obtained a substance between chlorine and iodine, Balard first thought it was idodine chloride before recognizing it as a new element. It seems unclear who exactly from Balard or Gay-Lussac thought of the name <em>br\u00f4me<\/em> but we know it comes from the Greek <em>bromos<\/em>, stench \u2014 a fair description of gaseous bromine. In addition to its rather unpleasant smell, bromine is also toxic \u2014 as Rattley puts it, bromine\u2019s orange-brown colour is convenient because \u201cavoid it you should\u201d. In the sunlight, elemental bromine (Br<sub>2<\/sub>) splits into radicals that readily attack other species, including lung tissues.<\/p>\n<p>Brominated compounds have been used throughout history for a variety of purposes, with varying degrees of success \u2014 find out in the <a href=\"https:\/\/www.nature.com\/nchem\/journal\/v4\/n6\/full\/nchem.1361.html\">article<\/a> how one was dangerous (likely lethal, really) to ancient Egyptians in the seemingly mundane form of a lipstick. More successful applications include that of potassium bromide, which acts on the nervous system, as an efficient epilepsy remedy, an anticonvulsant and a sedative during the late-19<sup>th<\/sup> and 20<sup>th<\/sup> centuries. It still is used in veterinary medicine, but bromide\u2019s chronic toxicity has since put a stop to human uses. Other instances have also exploited toxicity \u2014 Rattley mentions the insecticide chlorenapyr, whose rather peculiar structure comprises three different halogens \u2014 while in others no particular problems arose. A polybrominated dye for example has been widely used to stain various cell components for imaging purposes.<\/p>\n<p align=\"left\">In light of such diversity, it certainly doesn\u2019t seem unreasonable to think that bromine will continue to feature prominently both in research and practical applications.<\/p>\n<p align=\"left\">Anne<\/p>\n<p align=\"left\">Anne Pichon (Associate Editor, <em><a href=\"https:\/\/www.nature.com\/nchem\/index.html\">Nature Chemistry<\/a><\/em>)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>At first sight bromine seems to be \u2018just another halogen\u2019, a helpful counter-anion or leaving group in SN2 or cross-coupling reactions. Of course this isn\u2019t the whole story, as Matt Rattley \u2014 a chemistry student at the University of Oxford and the author of the winning essay on bromine for last year\u2019s contest \u2014 points out in his article (subscription required).&nbsp; <a href=\"https:\/\/blogs.nature.com\/thescepticalchymist\/2012\/06\/ambiguous-bromine.html#wpn-more-3711\" class=\"more-link\">Read more<\/a> <a href=\"https:\/\/blogs.nature.com\/thescepticalchymist\/2012\/06\/ambiguous-bromine.html\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":326,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25,8],"tags":[],"class_list":["post-3711","post","type-post","status-publish","format-standard","hentry","category-anne-pichon","category-in-your-element"],"_links":{"self":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/posts\/3711","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/users\/326"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/comments?post=3711"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/posts\/3711\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/media?parent=3711"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/categories?post=3711"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nature.com\/thescepticalchymist\/wp-json\/wp\/v2\/tags?post=3711"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}